Description: For this NASA STTR program, we propose to develop a novel superlattice-based near infrared to midwave infrared avalanche photodetector (APD) grown on InP substrates for single photon counting applications at high operating temperatures on the order of 200K accessible using thermoelectric coolers. This enables a detector with broad spectral response spanning 0.9 to 4 μm wavelength with reduced cooling requirements, offering a reliable detector technology with small size weight and power requirements that is ideal for future planetary missions. The detector is based on Princeton Lightwave's industry-leading planar-geometry single photon counting APD detector platform designed for 1.55 μm wavelengths, with incorporation of a novel absorber region.

Benefits: For commercial applications, the reduced cooling requirements significantly reduce the cost of the detector since the packaging requirements are much simpler and have higher yield compared to cryogenic cooling. The broad band detection with high sensitivity has many commercial uses such as in industrial sensing, spectroscopy, security, defense, and biomedical (molecular spectroscopy) applications. Furthermore, there are currently no detector technologies that provide true single photon sensitivity extending into the MWIR wavelength range. This dramatic increase in detector capability can be used to provide higher level system performance (e.g., detection of weaker signals or detection over longer distances ) or to relax other system-level requirements (e.g., launched laser power in active sensing systems). Military applications include laser radar for target identification and detection, night vision, infrared thermal sensors, and remote sensing. Homeland Security-related applications involve the remote scanning of public areas and government buildings for chemical and biological agent detection.

Potential NASA applications of our product is in-situ compositional analyses, deep space Earth long distance optical communication links, 3-D planetary terrain mapping, and Robot arm compatible time-gated detectors (and arrays). These systems aboard spacecrafts carry vital roles in the mission millions of miles away from Earth. These instruments designed for remote planetary missions have stringent requirements on reliability, size, weight and power. The reliability is of great concern, since the entire goal of the mission may be jeopardized if a malfunction occurs while at the remote destination. The instrument's size and weight and power needs to be reduced to reduce mission cost. Our detector is a solid state broadband detectors that can address all of these concerns, by providing a by replacing more bulkier and power consuming devices.